Piezoelectric oscillator and its manufacturing method

ABSTRACT

A piezoelectric oscillator comprising a piezoelectric vibrator with a piezoelectric vibrating element housed in a package and bottom terminals formed on the outer side of the bottom of the package, a circuit board with at least one electronic circuit component mounted and conductor patterns formed on the top side, and columnlike supports which mechanically and electrically connects the bottom terminals of the piezoelectric vibrator and the conductor patterns on the circuit board. The piezoelectric oscillator has a smaller board occupation area, and can be manufactured by quantity production using a batch process at a high productivity and a reduced cost.

FIELD OF THE INVENTION

[0001] The present invention relates to the construction and themanufacturing method of a piezoelectric oscillator, more particularly apiezoelectric oscillator of a construction in which a packagedpiezoelectric vibrator is fixed above a circuit board with circuitcomponents mounted thereon.

BACKGROUND ART

[0002] In a rapid progress in lowering of price and miniaturization withthe popularization of mobile communication devices such as cell phones,demand for lower price, smaller size, and lower profile are increasingof piezoelectric oscillators such as crystal oscillators. In response tosuch demands, not only packaging of crystal vibrators but also theintegration of an oscillating circuit including a frequency adjustmentcircuit and a temperature-compensating circuit is made to reduce thenumber of parts and the size of devices.

[0003]FIG. 11(a) is an exploded perspective view of a conventionalcrystal oscillator as an example of conventional piezoelectricoscillators. FIG. 11(b) is a longitudinal cross-sectional view of thecrystal oscillator.

[0004] This crystal oscillator 1 has a construction in which a crystalvibrator 11 is mounted on the top of a lower package 2 formed of ceramiclaminations to integrate them into a single device.

[0005] The lower package 2 has an outer frame 3 raised along the edge soas to surround the inner part. An IC 6 is fixed to the inner side of thebottom in the depression 4 by means of a binder 5 such as solder, andthe terminals 6 a formed on the top side of the IC6 and the bonding pads7 formed on the inner side of the bottom of the depression are connectedby bonding wires 8. In the case of forming the terminals on the bottomside of the IC, the IC may be flip-chip-mounted by connecting theterminals of the IC with the bonding pads 7 by ball bonding. Externalterminals 9 for surface mounting are formed on the outer side of thebottom of the lower package 2, and the external terminals 9 areconnected with the bonding pads 7 by means of conductors not shown inthe figure. Top terminals 10 are formed on the top side of the outerframe 3, which are connected with the bonding pads 7. The depression 4may be filled with an insulating resin to embed the IC 6 in a resin ifnecessary.

[0006] The crystal vibrator 11 has a construction in which a crystalvibrating element 14 is mounted in the depression 13 of a package 12formed of ceramic laminations, and the depression 13 is hermeticallysealed by a metal cover 15. Bottom terminals 16 are formed on the outerside of the bottom of the package 12. The bottom terminals 16 are bondedto the top terminals 10 of the lower package 2 by means of a binder suchas a conductive adhesive, and the depression 4 of the lower package 2 isclosed by the crystal vibrator 11.

[0007] This crystal vibrator 1 could be realized by integrating allcircuit components making up an oscillating circuit and atemperature-compensating circuit except the crystal vibrator 11 into asingle chip IC 6.

[0008] However, to produce the piezoelectric oscillator using theabove-described expensive IC 6 with all circuit components integratedinto it, it is a prerequisite that there is an expectation of a certainamount of quantity production of the piezoelectric oscillator 1 itself.Without an expectation of quantity production, cost reduction isdifficult. Since it is therefore impossible costwise to use this type ofexpensive IC 6 for piezoelectric oscillators manufactured in large itemsmall volume production, for example. Hence the circuit components formaking up the above-described circuits such as transistors, resistorsand capacitors, instead of the IC 6, must be mounted in the depression 4of the lower package 2 in the form of separate chip-shaped parts.

[0009] When attempting to mount such chip-shaped circuit components inthe depression 4 of the lower package 2 shown FIG. 11, they must bemounted on the lands (formed for mounting chip-shaped circuit componentsinstead of the bonding pads 7) by reflow soldering using cream solder.Application of cream solder to the lands is usually carried out byscreen printing using silk screens (masks). However, in the case of thelower package 2 where there is an elevated part, outer frame 3, aroundthe surface on which the lands are formed, the silk-screen printingtechnique cannot be used. It is therefore difficult to increase theproductivity by a batch process using the silk-screen printing, andapplication of cream solder to the lands in the depression 4 must becarried out one by one by a dispenser. This causes an increase in costif chip-shaped parts are used.

[0010] For this reason, in the case of constructing a piezoelectricoscillator using discrete chip-shaped parts, there is no choice but touse a construction in which lands are formed on the top side of alarge-area circuit board and chip-shaped parts 21 and a crystal vibrator22 are mounted on the lands by reflow soldering as shown in FIG. 12.Since the circuit board 20 of this construction is flat withoutdifferences in level and hence the silk-screen printing can be used toapply cream solder to the lands formed on it, a batch process using alarge circuit board block, which consists of a large number of thecircuit boards for the piezoelectric oscillators arranged side by sidein the vertical and horizontal directions, can be used.

[0011] However, since all components 21 and 22 are mounted on a flatcircuit board, this construction consequently needs a larger boardoccupation area, bringing a result against the demand for parts suitablefor high density mounting.

[0012] A purpose of the present invention is therefore to provide apiezoelectric oscillator which can use a flat circuit board to mountcircuit components, making it possible to apply cream solder to thelands formed on the circuit board in a batch process for mass productionand whose board occupation area can be reduced by three-dimensionallyarranging a packaged piezoelectric vibrator above the circuit board.

[0013] Another purpose of the present invention is to provide a methodof manufacturing the piezoelectric oscillator which makes efficientproduction using a batch process possible.

SUMMARY OF THE INVENTION

[0014] The above-described purposes are accomplished by the followinginventions:

[0015] The invention of claim 1 is a piezoelectric oscillatorcharacterized by comprising a piezoelectric vibrator with apiezoelectric vibrating element housed in a package and bottom terminalsformed on the outer side of the bottom of the package, a circuit boardwith at least one electronic circuit component mounted and conductorpatterns formed on the top side, and columnlike supports whichmechanically and electrically connects the bottom terminals of thepiezoelectric vibrator and the conductor patterns on the circuit board.

[0016] The invention of claim 2 is a piezoelectric oscillator comprisinga flat circuit board with circuit components making up an oscillatingcircuit mounted on the top side and external terminals formed on thebottom side and a piezoelectric vibrator fixed above the circuit boardwith a predetermined space by columnlike supports fixed to the top sideof the circuit board, characterized in that the piezoelectric vibratorhas a piezoelectric vibrating element hermetically sealed in a packageand bottom terminals connected with the excitation electrodes of thepiezoelectric vibrating element formed on the outer side of the bottomof the package; and the columnlike supports are separate parts from thepiezoelectric vibrator and the circuit-board, the bottom of thecolumnlike supports being mechanically and electrically fixed to landsformed on the top side of the circuit board, and the top of thecolumnlike supports being mechanically and electrically bonded to thebottom terminals of the piezoelectric vibrator.

[0017] The invention of claim 3 is a piezoelectric oscillator comprisinga flat circuit board with at least circuit components making up anoscillating circuit mounted on the top side and external terminalsformed on the bottom side and a piezoelectric vibrator, fixed togetherand electrically connected by means of columnlike supports,characterized in that: the columnlike supports are small pieces of aninsulating material with conductors formed on the top and the bottom andconnected by a connecting conductor; the circuit board hassupport-fixing lands for bonding the conductors on the bottoms of thecolumnlike supports thereto formed on the top side; and thepiezoelectric vibrator houses a piezoelectric vibrating element in ahermetically sealed package and has bottom terminals to be bonded to theconductors on the tops of the columnlike supports formed on the bottomof the package.

[0018] The invention of claim 4 is a piezoelectric oscillator of any oneof claims 1 to 3, wherein said columnlike supports are ceramic blockswith conductors formed on the top and the bottom and connected by aconnecting conductor.

[0019] The invention of claim 5 is the piezoelectric oscillator of anyone of claims 1 to 3, wherein said columnlike supports are metal blocksor metal balls.

[0020] The invention of claim 6 is a piezoelectric oscillator of any oneof claims 1 to 3, wherein circuit components with the highest mountedheight are used for said columnlike supports.

[0021] The invention of claim 7 is a piezoelectric oscillator of any oneof claims 1 to 6, wherein said columnlike supports are circular,elliptic, or oval in cross section.

[0022] The invention of claim 8 is a method of manufacturing apiezoelectric oscillator comprising a flat circuit board with at leastcircuit components making up an oscillating circuit mounted on the topside and external terminals formed on the bottom side and apiezoelectric vibrator fixed together and electrically connected bycolumnlike supports with conductors formed on the top and bottom andconnected by a connecting conductor, characterized by comprising thefollowing steps: forming the circuit patterns, support-fixing lands andterminals for the piezoelectric oscillator in each partition on a largemother circuit board; mounting the circuit components for thepiezoelectric oscillator on each partition on the mother circuit boardto form a block of the circuit boards of the piezoelectric oscillators;making a block of the columnlike supports which are disposed to fit onthe support-fixing lands of the corresponding circuit boards of theblock of the circuit boards, and fixing the columnlike supports of theblock of the columnlike supports to the support-fixing lands on thecorresponding circuit boards of the block of the circuit boards,electrically connecting the conductor on the bottom of each columnlikesupport and the support-fixing land by putting the block of thecolumnlike supports onto the block of the circuit boards; cutting theblock of the circuit boards together with the block of the columnlikesupports to separate the individual circuit boards, and mounting thecrystal vibrator on the columnlike supports of each circuit board bybonding the bottom terminals of the piezoelectric vibrator to theconductors on the tops of the columnlike supports.

[0023] The invention of claim 9 is a method of manufacturing apiezoelectric oscillator of claim 8, wherein the block of the columnlikesupports comprises a latticework part with holes corresponding to thecircuit boards of the block of the circuit boards and the columnlikesupports projecting from the latticework part into each hole so as tofit on the support-fixing lands of the corresponding circuit board.

[0024] The invention of claim 10 is a piezoelectric oscillatorcomprising a flat circuit board with circuit components making up anoscillating circuit mounted on the top side and bottom terminals formedon the bottom side and a piezoelectric vibrator held above the circuitboard with a predetermined space by a support frame, characterized inthat; the piezoelectric vibrator has a piezoelectric vibrating elementhoused in a hermetically sealed package and bottom terminals on theouter side of the bottom of the package; the support frame has terminalsfor connecting the bottom terminals of the piezoelectric vibratorthereto on the top side and terminals for being connected to the circuitboard formed on the bottom side; and the circuit board has a largersurface area than the outside dimensions of the support frame, and haslands for connecting the bottom terminals of the support frame theretoand lands for mounting circuit components thereon inside and outside thesupport frame on the top side of the circuit board.

[0025] The invention of claim 11 is a piezoelectric oscillator of claim10, wherein a plurality of metals are used instead of the support frame.

[0026] The invention of claim 12 is a piezoelectric oscillatorcomprising a flat circuit board with circuit components making up anoscillating circuit mounted on the bottom side and external terminalsformed on the top side and a piezoelectric vibrator with bottomterminals formed on the bottom of the package, fixing together bybonding the external terminals of the circuit board and the bottomterminals of the piezoelectric vibrator; and metal balls serving assupports and external terminals are fixed to the bottom side of thecircuit board.

[0027] The invention of claim 13 is a piezoelectric oscillator,characterized by having a piezoelectric vibrating element housed in ahermetically sealed package, circuit patterns for an oscillating circuitand lands for fixing supports thereto formed on the bottom of thepackage, and circuit components and metal balls serving as supports andexternal terminals mounted on the bottom.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028]FIG. 1 is a longitudinal sectional view of the fist embodiment ofthe piezoelectric oscillator according to the present invention.

[0029] FIGS. 2 is a side view showing the construction of a variation ofthe piezoelectric oscillator of the fist embodiment of the piezoelectricoscillator according to the present invention.

[0030] FIGS. 3 is a side view showing the construction of anothervariation of the piezoelectric oscillator of the fist embodimentaccording to the present invention.

[0031] FIGS. 4(a) to (c) shows a possible protrusion of the columnlikesupports from the edge of the circuit board by disposition.

[0032] FIGS. 5(a) and (b) are a sectional view and an explodedperspective view of the third embodiment of the piezoelectric oscillatoraccording to the present invention.

[0033]FIG. 6 shows a method of manufacturing the third embodiment of thepiezoelectric oscillator according to the present invention.

[0034] FIGS. 7(a) and (b) are a sectional view and an explodedperspective view of the fourth embodiment of the piezoelectricoscillator according to the present invention.

[0035] FIGS. 8(a) and (b) are a sectional view and a plan view of thefifth embodiment of the piezoelectric oscillator according to thepresent invention.

[0036] FIGS. 9 is a sectional view of the sixth embodiment of thepiezoelectric oscillator according to the present invention.

[0037] FIGS. 10(a) and (b) are a sectional view and a bottom view of theseventh embodiment of the piezoelectric oscillator according to thepresent invention.

[0038] FIGS. 11(a) and (b) are an exploded perspective view and asectional view of a conventional piezoelectric oscillator.

[0039]FIG. 12 shows a mounting method of the circuit components on thecircuit board of a conventional piezoelectric oscillator.

DETAILED EXPLANATION OF THE PREFERRED EMBODIMENTS

[0040] The present invention is described below in detail with referenceto the embodiments shown in the drawings.

[0041] Referring to FIGS. 1 to 3, the first embodiment of thepiezoelectric oscillator according to the present invention isdescribed. The first embodiment is a piezoelectric oscillator 31comprising a circuit board 32 with circuit components 33 making up anoscillating circuit and a temperature-compensating circuit mounted onthe lands 35 formed on the top side and external terminals 34 formed onthe bottom side and a piezoelectric vibrator 41 fixed above the top sideof the circuit board 32 with a predetermined space, characterized inthat the piezoelectric vibrator 41 is fixed above the piezoelectricvibrator by means of columnlike supports 50 which are separate partsfrom both the circuit board 32 and the piezoelectric vibrator 41 andwhose bottoms are mechanically and electrically fixed to thesupport-fixing-lands 36 formed on the top side of the circuit board 32and whose tops the bottom terminals of the piezoelectric vibrator aremechanically and electrically bonded to.

[0042] First, the example shown in FIG. 1 has a construction in whichthe columnlike supports 50 are fixed to the support-fixing lands 36 onthe flat ceramic circuit board 32 and a crystal vibrator 41 is mountedon the tops of the columnlike supports 50. The circuit board 32 has thecircuit components 33 mounted on the lands 35 formed on the top side,and has external terminals 34, each connected with the correspondinglands 35, formed on the bottom side. Further, the circuit board 32 hasthe support-fixing lands 36 formed on the top side.

[0043] The piezoelectric vibrator 41 comprises a package 42 consistingof the main body of package 42 a with a depression and a metal cover 42b hermetically sealing the depression and a crystal vibrating element45. The main body of package 42 a is provided with bottom terminals 46on the bottom. The bottom terminals 46 are connected to the electrodesof the crystal vibrating element 45. The package 42 is made of ceramic,for example.

[0044] The columnlike supports 50 of this embodiment each comprise aceramic block 51 in the shape of a polygonal prism such as a squareprism (about 0.3 to 0.5 mm in thickness), bottom terminal 52 (metallizedarea) formed on the bottom end of the ceramic block 51, top terminal 53(metallized area) formed on the top end of the ceramic block 51, andconductor 54 electrically connecting the bottom terminal 52 and the topterminal 53.

[0045] Since the columnlike supports 50 of this embodiment are separateparts from both the circuit board 32 and the crystal oscillator 41, theycan be fixed to the support-fixing lands 36 on the circuit board 32 byapplying cream solder to the support-fixing lands 36 using silk-screenprinting and reflowing the solder. In the silk-screen printing process,application of cream solder to the lands 35 is carried out at the sametime. The circuit components 33 and the columnlike supports 50 are thenplaced on the lands 35 and the support-fixing lands 36. The circuitboard 32 with the circuit components 33 and the columnlike supports 50placed on it is heated in a reflow furnace and then cooled down. Thecircuit components 33 and the columnlike supports 50 are thereby joinedto the circuit board 32.

[0046] The crystal vibrator 41 may be fixed to the columnlike supports50 by bonding the bottom terminals 46 to the top terminals 53 of thecolumnlike supports 50 with a conductive adhesive or any other meansafter the columnlike supports 50 are fixed to the circuit board 32. Thecrystal vibrator 41 may also be joined to the columnlike supports 50 atthe same time as the circuit components 33 and the columnlike supports50 are joined to the circuit board 32. Since the columnlike supports 50are separated parts from both the circuit board 32 and the crystalvibrator 41, it is made possible to carry out the mounting and joiningof the circuit components 33 and the columnlike supports 50 to a largenumber of the circuit boards 32 in a batch process. More specifically,cream solder is applied to all lands 35 and 36 on a large-area mothercircuit board, which is formed of a plurality of the circuit boards forthe piezoelectric oscillators connected side by side in the vertical andhorizontal directions, by silk-screen printing. The circuit components33 and the columnlike supports 50 are then put on the lands 35 and 36,and the mother circuit board is heated in a reflow furnace to join thecircuit components and the columnlike supports to the lands 35 and 36.By this batch process, the productivity of the piezoelectric oscillatorscan be significantly increased.

[0047] In addition, since the crystal vibrator 41 is held above the topside of the circuit board 32 with a predetermined space in parallel withthe top side, the circuit components can be mounted under the crystalvibrator 41 and hence the area required to mount the piezoelectricoscillator 31 can be decreased.

[0048] Furthermore, by disposing the columnlike supports 50 only betweenthe terminals 46 and the support-fixing lands 36 and making the bottomarea of each columnlike support 50 as narrow as possible, the effectivearea on the top side of the circuit board 32, which is used to used tomount the circuit components thereon, can be increased.

[0049] In another example of the first embodiment, metal blocks in theshape of a polygonal prism such as a square prism about 0.3 to 0.5 mm inthickness, instead of the ceramic blocks 51, are used for the columnlikesupports 50. By using the columnlike supports made of a conductivematerial and joining them to the support-fixing lands 36 and the bottomterminals 46 of the crystal vibrator by soldering or any other method,the same construction as the piezoelectric oscillator shown in FIG. 1can be realized. By this example, the process for forming the terminals52 and 53 and connecting conductors 54 required in the case of usingceramic blocks can be eliminated.

[0050] Further, metal balls about 0.3 to 0.5 mm in diameter, instead ofmetal blocks, may also be used for the columnlike supports 50 as shownin FIG. 2. The metal balls can be joined to the support-fixing lands 36and the bottom terminals 46 of the crystal vibrator by reflow-solderingwith cream solder or by bonding with a conductive adhesive.

[0051] In this case, as well as in the case of using metal blocks, theprocess for forming the terminals 52 and 53 and connecting conductors 54required in the case of using ceramic blocks can be eliminated.

[0052]FIG. 3 shows still another example of the first embodiment of thepiezoelectric oscillator according to the present invention. The sameparts as those of the embodiment shown in FIG. 1 are represented by thesame numerals. This embodiment differs from that of FIG. 1 in using thehighest circuit components 33A among the chip-shaped circuit components33 for the columnlike supports 50.

[0053] In the example shown in FIG. 3, two or more circuit components33A having the highest mounted height are mounted at the positions ofthe circuit components, and the crystal vibrator 41 are fixed to thetops of the circuit components 33A. The tops of the circuit components33A are provided with terminals for electrical connection with thebottom terminals 46 of the crystal vibrator 41. Conductors forconnecting the top terminals with the circuit on the circuit board arealso formed, though not shown in the figure.

[0054] It is an important condition that the circuit components 33A usedfor the columnlike supports have substantially the same height, buttheir disposition on the circuit board 32 is not limited to that shownin the figure.

[0055] By this embodiment, since two or more circuit components selectedfrom the circuit components 33 are used for the columnlike supports, thenumber of the parts can be decreased, the cost can be reduced, and thearea of the circuit board 32 can be made smaller.

[0056] FIGS. 4(a) and (b) show the bottom shapes of the columnlikesupports of the second embodiment of the piezoelectric oscillatoraccording to the present invention. This embodiment uses the columnlikesupports 50 whose bottom shape (cross section) is a circle or an ellipse(including oval). By using the columnlike supports of such a round crosssection, the columnlike supports can be prevented from protruding fromthe edge of the circuit board 32 if they move out of place in thedirection of rotation in the process for fixing them to the circuitboard 32.

[0057] In the case where the shape of the bottom of the columnlikesupports 50 is a polygon, e.g. a rectangle as shown in FIG. 4(c), thecolumnlike supports are fixed to the circuit board 32 with a cornerportion protruded from the edge of the circuit board 32 if thecolumnlike supports 50 move out of the correct position shown by thebroken line in the direction of rotation for some reason or other. Theprotruded corner portion can form a burr which can cause problems.

[0058] However, by forming the bottom of the columnlike supports 50 inthe shape of a circle or ellipse without corners as shown in FIGS. 4(a)and 4(b), the columnlike support 50 does not readily protrude from theedge of the circuit board if it moves out of the correct position in thedirection of rotation. Further, if the side of the columnlike support 50slightly protrudes from the edge of the circuit, the protruded part,unlike a protruded corner, does not form a burr which can causeproblems.

[0059] FIGS. 5(a) and (b) show a longitudinal section and an explodedperspective view of the third embodiment of the piezoelectric oscillatoraccording to the present invention. The piezoelectric oscillator shownin the figures comprises a circuit board 32 with circuit components 33making up an oscillating circuit and a temperature-compensating circuitmounted on the lands 35 formed on the top side and external terminals 34formed on the bottom side and a crystal vibrator 41 held above the topside of the circuit board 32 with a predetermined space by columnlikesupports 55 fixed to the top side of the circuit board 32. The bottomterminals 56 on the bottoms of the columnlike supports 55 aremechanically and electrically fixed to the support-fixing lands 57formed on the top side of the circuit board 32, and the top terminals 58on the tops of the columnlike supports 55 are mechanically andelectrically fixed to the bottom terminals 46 of the crystal vibrator41.

[0060] The columnlike supports 55 are made by forming holes in a ceramicplate as described later in detail. The ceramic plate has a thicknessequal to the predetermined height of the columnlike supports, which isgreater than the highest mounted height of the circuit components 33 onthe circuit board 32. The columnlike supports 55 have a bottom terminal56 and a top terminal 58 formed on the bottom and top sides, and aconductor connecting both terminals.

[0061] The crystal vibrator 41 is mounted on the columnlike supports 55by bonding the bottom terminals to the top electrodes of the columnlikesupports 55 with a conductive adhesive after the columnlike supports 55are fixed to the circuit board 32.

[0062]FIG. 6 shows the method of manufacturing the circuit boards andthe columnlike supports and the method of fixing the columnlike supportsto the circuit boards in the case of the third embodiment. As shown inthe figure, a large number of the circuit boards 32 for thepiezoelectric oscillators are formed on a large-area mother circuitboard to produce a circuit board block 60, and a large number of thecolumnlike supports for the piezoelectric oscillators are formed in alarge-area mother ceramic plate 61 to produce a columnlike supportsblock 62.

[0063] More specifically, the columnlike supports block 62 consists of alatticelike part defining the holes corresponding to the circuit boards32 of the circuit board bock 60 and columnlike supports 55 projectinginto the holes from the latticelike part. The columnlike supports block62 are produced by forming holes in a mother ceramic plate 61. Thecolumnlike supports 55 are disposed so as to fit on the correspondingsupport-fixing lands 57 on the corresponding circuit boards 32. The topand bottom sides of the columnlike supports block 61 are metallized. Thecolumnlike supports 55 have one or more through holes for connecting themetal layers on the top and bottom sides formed at predeterminedpositions. The thickness of the columnlike supports block 61 isdetermined according to the heights of the circuit components 33 mountedon the circuit board 32.

[0064] Next, the method of fixing the columnlike supports to the circuitboards of the piezoelectric oscillators is described below.

[0065] After the circuit board block 60 is manufactured, cream solder isapplied to all the lands 35 for the circuit components 33 on the circuitboard block 60 by silk-screen printing, the circuit components 33 areplaced onto the lands, the circuit board block 60 with the circuitcomponents thereon is heated in a reflow furnace, and the circuit-formedboard 60 is cooled to join the circuit components 33 to the lands.

[0066] Thereafter or separately, the columnlike supports block 61 ismanufactured by forming holes in a mother ceramic plate 61. Next, aconductive adhesive is applied to the support-fixing lands 57 of thecircuit boards 32 of the circuit board block 60, and the columnlikesupports block 61 is placed on the circuit board block 60, aligning theposition of the columnlike supports block 62 with the circuit boardblock 60 so that the columnlike supports fit on the correspondingsupport-fixing lands 57. The columnlike supports in columnlike supportsblock 61 are thus bonded to the support-fixing lands of the circuitboard block 60 at one time. The circuit board block 60 and thecolumnlike supports block 61 are then cut together along the positionshown by the broken line by means of a dicing saw, and the circuit board32 with the circuit components 33 and the columnlike supports 55 mountedthereon are separated.

[0067] In another method of fixing the columnlike supports 55 of thecolumnlike supports block 61 to the support-fixing lands 57 on thecircuit board block 60, first the columnlike supports 55 of thecolumnlike supports block 61 are bonded to the support-fixing lands 57on the circuit board block 60 with a conductive adhesive. Next, creamsolder is applied to the lands 35 for the circuit components 33 bysilk-screen printing, the circuit components 33 are mounted, and thecircuit components 33 are joined to the lands 35 by heating in a reflowfurnace.

[0068] In still another method of fixing the columnlike supports 55 ofthe columnlike supports block 61 to the support-fixing lands 57 on thecircuit board block 60, cream solder is applied to the lands 35 for thecircuit components 33 and the support-fixing lands 57, the circuitcomponents are mounted on the lands 35, the columnlike supports block 61is placed on the circuit board block 60, and the circuit components 33and the columnlike supports 55 are joined to the lands 35 and thesupport-fixing lands 57 by heating in a reflow furnace.

[0069] By this method, since the columnlike supports are manufactured byforming a plurality of the columnlike supports in a single motherceramic plate, the heights of the columnlike supports are accurately thesame, defects in mounting of the crystal oscillators caused by thedimensional errors in the height of the columnlike supports can beprevented. In addition, since the columnlike supports can be fixed to alarge number of the circuit boards in a batch by placing a columnlikesupports block on a circuit board block, an effective production is madepossible.

[0070] Further, by using a columnlike supports block formed in alarge-area mother ceramic plate, it is made unnecessary to mount thecolumnlike supports on the support-fixing lands on each circuit boardone by one. Further, since the top and bottom orientation of thecolumnlike supports, which is important when mounting the columnlikesupports, is fixed, mounting errors of the columnlike supports can beprevented. Furthermore, displacement of the columnlike supports out ofthe lands which can occur when the columnlike supports are put on creamsolder can be prevented. Consequently, the efficiency of themanufacturing process is significantly improved.

[0071] After the circuit board 32 with the circuit components 33 and thecolumnlike supports 55 mounted thereon is manufactured, a conductiveadhesive is applied to the top terminals 58 of the columnlike supports55, and the bottom terminals 46 of the crystal vibrator 41 are bonded tothe top terminals 58 to complete the piezoelectric oscillator.

[0072] Though the case of using ceramic columnlike supports isexplained, columnlike supports made of glass epoxy or any other resinmay also be used. By using the columnlike supports made of such amaterial, shocks applied to the crystal oscillator can be absorbed.

[0073] FIGS. 7(a) and 7(b) show the fourth embodiment of thepiezoelectric oscillator according to the present invention, FIG. 7(a)being a sectional view, and FIG. 7(b) an exploded perspective view. Thisembodiment is characterized in that the size of the circuit board formounting the circuit components thereon is a little larger than that ofthe crystal vibrator held above the circuit board by means of a supportframe. By this construction, a circuit components-mountable area whichare not covered by the mounted crystal vibrator is made available, andcircuit components such as capacitors for fine adjustment of theoscillating frequency can be mounted on the area for addition or easyreplacement. Further, since the circuit components are all mounted on aflat surface, application of cream solder by silk-screen printing can beused.

[0074] Specifically, the fourth embodiment has a construction in which aflat circuit board 71 with circuit components 33 making up anoscillating circuit and a temperature-compensating circuit and circuitcomponents 70 for adjustment of the oscillating frequency mounted on thetop side and external terminals 34 formed on the bottom side and acrystal vibrator 41 held above with a predetermined space by a supportfame 72 attached to the top side of the circuit board 71 are integratedinto a single piezoelectric oscillator.

[0075] On the top side of the circuit board 71, lands 35 for mountingcircuit components making up an oscillating circuit and atemperature-compensating circuit thereon, lands 73 for mounting circuitcomponents 70 for adjustment of the oscillating frequency, and lands 36for fixing a support frame 72 are formed. The circuit components 33 and70 and the support frame 72 are joined to the circuit board 71 byapplying cream solder to the lands using silk-screen printing, placingthe circuit components 33 and 70 and the support frame 72 on the lands,and reflowing the solder. Since the circuit components 70 for adjustmentare mounted outside the support frame 72, replacement or addition of thecircuit components 70 for adjustment can be easily made when a fineadjustment of the oscillating frequency is required.

[0076] The support frame 72 may be fixed to the circuit board 71 bybonding it to the lands 36 with a conductive adhesive after the circuitcomponents 33 and 70 are joined to the lands 35 and 37 by reflowsoldering.

[0077] The crystal vibrator 41 has a construction in which a crystalvibrating element 45 is mounted in the depression of a ceramic package42 a and the depression is hermetically sealed by a metal cover.External terminals 46, which are connected with the electrodes of thecrystal vibrating element 45, are formed on the outer side of the bottomof the ceramic package 42.

[0078] The crystal vibrator 41 is then mounted on the support frame 72by bonding the external terminals 46 to the top terminals 74 of thesupport frame 72 to complete the piezoelectric oscillator.

[0079] FIGS. 8(a) and (b) show the fifth embodiment of the piezoelectricoscillator according to the present invention. FIG. 8(a) is a sectionalview and FIG. 8(b) is a plan view showing the top view of the circuitboard with circuit components and supports mounted thereon. Thedifference of the fifth embodiment from the fourth embodiment is thatthe fifth embodiment uses metal balls, instead of the support frame, areused for holding the crystal vibrator above the circuit board with apredetermined space.

[0080] Specifically, the fifth embodiment has a construction in which aflat circuit board 71 with circuit components 33 making up anoscillating circuit and a temperature-compensating circuit and circuitcomponents 70 for adjustment of the oscillating frequency mounted on thetop side and external terminals 34 formed on the bottom side and acrystal vibrator 41 held above with a predetermined space by a metalballs 80 fixed to the top side of the circuit board 71 are integratedinto an oscillator.

[0081] On the top side of the circuit board 71, lands 35 for mountingcircuit components making up an oscillating circuit and atemperature-compensating circuit thereon, lands 73 for mounting circuitcomponents 70 for adjustment of the oscillating frequency thereon, andlands 36 for fixing metal balls 80 are formed. The circuit components 33and 70 and the metal balls 80 are joined to the circuit board 71 byapplying cream solder to the lands using silk-screen printing, placingthe circuit components 33 and 70 and the metal balls 80 on the lands,and reflowing the solder. Since the circuit components 70 for adjustingthe oscillating frequency are mounted outside the space under thecrystal vibrator 41, the replacement or addition of the circuitcomponents 70 for frequency adjustment can be s easily made withoutremoving the crystal vibrator 41 and further the circuit components 33when an fine adjustment of the oscillating frequency is required asdescribed later.

[0082] Next, the crystal vibrator 41, which is constructed asillustrated in FIG. 7, is mounted on the balls 80 bonding the externalterminals 46 to the metal balls by means of a conductive adhesive orsolder to complete the piezoelectric oscillator.

[0083] The circuit components 33 and 70 and the metal balls 80 may alsobe fixed to the circuit board 71 with a conductive adhesive to preventsolder from melting because of an excessive rise in temperature of thepiezoelectric oscillator, thereby causing the circuit components and themetal balls to move out of place.

[0084] Since ball-shaped supports, unlike prism-shaped supports, do nothave corners, the alignment of the mounted direction of the supports isnot required. The use of ball-shaped supports has therefore theadvantage of being able to simplify the fabricating process incomparison with the construction using prism-shaped supports.

[0085] Since ball-shaped supports, unlike a support frame 72 as shown inFIG. 7, do not have the side walls, the areas of the circuit board 71between the ball-shaped supports become available for mounting circuitcomponents as shown in FIG. 8(b). The use of ball-shaped supportstherefore increases the ratio of the circuit components-mountable areato the whole area of the circuit board, thereby making it possible tofurther decrease the area of the circuit board 71. This construction ishence effective in miniaturizing the piezoelectric oscillator.

[0086] Further, the circuit components 33 may be an IC chip. An IC chipis mounted on the circuit board 71 by the flip-chip bonding technique,for example, and then firmly fixed by injecting an adhesive into thespace between the circuit board and the IC chip.

[0087] The ball-shaped supports may be fixed to the circuit board 71with solder or a conductive adhesive. In addition, they may also befixed by the flip-chip bonding technique as the IC chips. In this case,the supports and IC chip can be mounted on the circuit board by the sameprocess, and hence the manufacturing process can be simplified.

[0088] In the case of using an IC chip, adjustment terminals forinputting adjustment signals may be required to make possible adjustmentof the circuit settings of the IC if necessary after the piezoelectricoscillator is assembled. The adjustment terminals may be formed on theouter side of the crystal vibrator 41.

[0089]FIG. 9 is a sectional view of the sixth embodiment of thepiezoelectric oscillator according to the present invention. The sixthembodiment is characterized in that the bottom of a crystal vibrator isfixed to the top side of a circuit board with circuit components mountedon the bottom side in order to further miniaturize a piezoelectricoscillator.

[0090] Specifically, the sixth embodiment has a construction in which aflat circuit board 84 with circuit components 33 making up anoscillating circuit and a temperature-compensating circuit and metalballs 80 mounted on the bottom side and external terminals 83 formed onthe top side and a crystal vibrator 41 are fixed together into a singlepiezoelectric oscillator by bonding the external terminals 46 of thecrystal vibrator 41 to the external terminals 83 on the top side of thecircuit board 84. The metal balls 80 serve as the supports and theterminals for external connection of the finished piezoelectricoscillator.

[0091] On the bottom side of the circuit board 84, lands 35 for mountingcircuit components 33, lands 36 for fixing metal balls 80 to the circuitboard 84 are formed. The circuit components 33 and the metal balls 80are joined to the circuit board 84 by applying cream solder to the landsusing silk-screen printing, placing the circuit components 33 and themetal balls 80 on the lands 35 and 36, and reflowing the solder.

[0092] Since the circuit components-mounted side (the bottom side) ofthe circuit board 84 is open, replacement or addition of circuitcomponents can be easily made if necessary for adjustment of theoscillating frequency or other reason.

[0093] The metal balls 80 may also be bonded to the lands 36 of thecircuit board 84 with a conductive adhesive after the circuit components33 are mounted on the lands 35 by reflow soldering. Further, since thecircuit board 84 is backed with the crystal vibrator 41 to maintain theflatness, a thinner circuit board can be used for the circuit board 84.

[0094] Next, the crystal vibrator 41, which is constructed as describedabove, is joined to the circuit board 84 by bonding the externalterminals 46 of the crystal vibrator 41 to the external terminals 83 ofthe circuit board 84 with a conductive adhesive to complete thepiezoelectric oscillator of this embodiment.

[0095]FIG. 10(a) is a sectional view of the seventh embodiment of thepiezoelectric oscillator according to the present invention. The seventhembodiment is characterized in that the circuit components making up anoscillating circuit and a temperature-compensating circuit and supportsare mounted on the outer side of the bottom of the package of a crystalvibrator by forming the circuit patterns and the lands for the circuitcomponents and the supports. This embodiment is intended to make thecircuit board 84 shown in FIG. 9 unnecessary, thereby lowering theprofile of the piezoelectric oscillator of the sixth embodiment.

[0096] Specifically, the seventh embodiment has a construction in whichcircuit patterns and lands 86 for circuit components and lands 87 forsupports 86 are formed on the outer side of the bottom of the ceramicpackage 42 a of the crystal vibrator 41, the circuit components of anoscillating circuit and a temperature-compensating circuit and metalballs 80 are mounted, a crystal vibrating element 45 is mounted in thedepression of the package 42 a; and the depression is the depression ishermetically sealed by a metal cover 42 b. The metal balls 80 also serveas the supports and the terminals for external connection.

[0097] The circuit components 33 and the metal balls 80 are mounted tothe outer side of the bottom of the ceramic package 42 a by applyingcream solder to the lands 86 and 87 using silk-screen printing, placingthe circuit components 33 and the metal balls 80 onto the lands 86 and87, and reflowing the solder.

[0098] Since the circuit components-mounted side, that is, the bottom ofthe crystal vibrator 41 is open, replacement or addition of circuitcomponents can be easily made if necessary for adjustment of theoscillating frequency or other reason.

[0099] The metal balls 80 may also be bonded to the lands 87 on thebottom of the ceramic package 42 a with a conductive adhesive after thecircuit components 33 alone are mounted on the lands 86 by reflowsoldering.

[0100] Further, the circuit components 33 and the metal balls 80 may bemounted to the lands 86 and 87 on the bottom of the ceramic package 42 aafter the crystal vibrator 41 is completed by mounting a crystalvibrating element 45 in the depression of the package 42 a andhermetically sealing the depression by means of a metal cover 42 b. Bythis method, only good crystal vibrators 41 can be used.

[0101] Although the sixth and seventh embodiments are described usingthe metal balls 80 for the supports, ceramic blocks with terminalsformed on the top and bottom sides and connected by a conductor, ormetal blocks, shaped like a polygonal prism such as triangular or squareprism or a round column such as circular column or elliptic column mayalso be used for the supports.

[0102] In the case of using polygonal column-shaped supports, thedirection of the mounted supports must be aligned so that a cornerportion of the polygonal column-shaped supports does not protrude fromthe edge of the circuit board if required.

[0103] In the case of using round column-shaped supports, the processfor aligning the direction of the mounted supports is not requiredbecause round column-shaped supports do not have corners. Roundcolumn-shaped supports therefore has the advantage of being able tosimplifying the fabricating process in comparison with polygonalcolumn-shaped supports.

[0104]FIG. 10(b) is a bottom view which shows the circuitcomponents-mounted side of the crystal vibrator 41 of the seventhembodiment and that of the circuit board 84 of the sixth embodiment.

[0105] As known from the figure, the sixth and seventh embodiments alsouse metal balls 80 for the support as the fifth embodiment, and hencecircuit components can be disposed between the metal balls 80 and 80′ asshown in FIG. 10(b). The sixth and seventh embodiments therefore have ahigher ratio of the circuit components-mountable area to the whole areaof the circuit board 84 or to the bottom of the crystal vibrator 41, andare effective constructions to miniaturize a piezoelectric oscillator.

[0106] Further, the circuit components 33 may be an IC chip. An IC chipis mounted on the lands 86 formed on the bottom of the crystal vibrator41 by the flip-chip bonding technique, for example, and may be furtherbonded to the crystal vibrator with an adhesive to firmly fix them.

[0107] The ball-shaped supports may be fixed to the bottom of thecrystal vibrator 41 with solder or a conductive adhesive. They may alsobe fixed by the flip-chip bonding technique as the IC chip. In thiscase, the supports and IC chip can be mounted on the bottom of thecrystal vibrator 41 by the same process, and hence the fabricatingprocess can be simplified.

[0108] Furthermore, in the sixth and seventh embodiments, at least oneof a plurality of the supports may be different from the others in shapeand/or size so that the terminals arrangement of the piezoelectricoscillator can be readily identified.

[0109] In the case where the columnlike supports are ceramic blocks suchthat terminals formed on the top and bottom are connected by a metallayer formed by metallization, the metal layer can be used as acastration(?) surface which makes it possible to visually check thecondition of connection by soldering when mounting the piezoelectricoscillator to a circuit board or mounting the crystal vibrator on thecircuit board.

[0110] As described above, the present invention provides apiezoelectric oscillator having a construction in which a circuit boardwith circuit components making up an oscillating circuit and atemperature-compensating circuit mounted on one side and a piezoelectricvibrator with a piezoelectric vibrating element housed in a package arejoined together into a single device. By using a flat circuit board tomake it possible to apply cream solder to the lands on the circuit boardby silk-screen printing, the piezoelectric oscillator is suitable formass production by a batch process. And by stacking the packaged crystalvibrator above the circuit board with a predetermined space in athree-dimensional arrangement, the area occupied by the piezoelectricoscillator is significantly reduced.

[0111] In addition, by using separate columnlike supports formechanically and electrically connecting the circuit board and thecrystal vibrator, quantity production by a batch process is madepossible.

[0112] As understood from the above description, the inventions includedherein are summarized as follows:

[0113] The invention of claim 1 holds a piezoelectric vibrator above acircuit board with circuit components making up an oscillating circuitand a temperature-compensating circuit mounted thereon and electricallyconnects the bottom terminals of the piezoelectric vibrator and thelands formed on the circuit board by means of columnlike supportsseparate from the piezoelectric vibrator and the circuit board.

[0114] This invention makes it possible to construct a piezoelectricoscillator with a decreased board occupation area using a flat circuitboard. Therefore, quantity production of the circuit boards by a batchprocess is made possible, and the footprint size of the piezoelectricoscillator can be made smaller.

[0115] The invention of claim 2 uses for the columnlike supports ceramicblocks each of which has a top terminal and a bottom terminal formed onthe top and the bottom, respectively, and connected with each other. Thecost of the columnlike supports can be reduced.

[0116] The invention of claim 3 uses metal blocks or metal balls for thecolumnlike supports. The construction of the columnlike supports can befurther simplified, the cost can be reduced, and the productivity can beincreased.

[0117] The invention of claim 4 uses the highest mounted height circuitcomponents for the columnlike supports. By this invention, thecolumnlike supports are not required, and the piezoelectric oscillatorcan be manufactured with a reduced number of parts.

[0118] The invention of claim 5 uses columnlike supports with acircular, elliptic or egg-shaped cross section. Therefore, no part ofthem protrudes from the edge of the circuit board and becomes burrs ifthey move out of position in the direction of rotation.

[0119] The inventions of claims 6 and 7 hold a piezoelectric vibratorwith a piezoelectric vibrating element housed in a hermetically sealedpackage above a circuit board with circuit components making up anoscillating circuit-and a temperature-compensating circuit mountedthereon and electrically connects the bottom terminals of thepiezoelectric vibrator and the lands formed on the circuit board bymeans of nonconductive supports separate from the piezoelectric vibratorand the circuit board, the nonconductive supports having terminalsformed on the top and the bottom and connected together by a conductor.By this invention, the top-viewed shape of the piezoelectric oscillatorcan be made smaller.

[0120] The invention of claim 8 is a method of manufacturing apiezoelectric oscillator in which a piezoelectric vibrator and a circuitboard with circuit components making up an oscillating circuit and atemperature-compensating circuit mounted thereon are joined togetherwith columnlike supports, each of columnlike supports being anonconductive body with terminals formed on the top and the bottom andconnected by a connecting conductor, put between them, comprising thefollowing steps: forming a plurality of the circuit boards for thepiezoelectric oscillators on one mother ceramic plate to produce acircuit board block by manufacturing a circuit board block consisting ofa plurality of the circuit boards for the piezoelectric oscillators byforming wiring patterns, lands and external terminals in each partitionon a mother circuit board and mounting the circuit components on eachcircuit board for the piezoelectric oscillator; manufacturing acolumnlike supports block consisting of a latticelike part defining theholes corresponding to the circuit boards of the circuit board bock andcolumnlike supports projecting into the holes from the latticelike partby forming holes in a large-area mother ceramic plate, and forming aconductor layer on the top and bottom side of the columnlike supportsblock and connecting the conductor layers on both sides of thecolumnlike supports block;

[0121] Bonding the columnlike supports of the columnlike supports blockto the corresponding lands of the circuit board block with a conductiveadhesive or solder by placing the columnlike supports block on thecircuit board block; cutting the circuit board block together with thecolumnlike supports block to separate the individual circuit boards; andmounting the piezoelectric oscillator on the columnlike supportsmechanically and electrically joining the bottom terminals of thepiezoelectric vibrator and the conductive layers on the top of thecolumnlike supports.

[0122] This method makes possible quantity production by a batchprocess, and the increased productivity makes possible a cost reduction.

[0123] The invention of claim 9 manufactures a columnlike supports blockconsisting of a latticelike part and columnlike supports projecting fromthe latticelike part into the spaces defined by the latticelike partlike a peninsula.

[0124] This method makes possible quantity production by a batchprocess, and the increased productivity makes possible a cost reduction.

[0125] The invention of claim 10 uses for the circuit board a circuitboard having a larger surface area than the outside dimensions of thesupporting frame for holding the piezoelectric vibrator and mountscircuit components such as capacitors for fine adjustment of theoscillating frequency on the area of the circuit board outside thesupport frame. This invention makes it possible to make fine adjustmentof the oscillating frequency.

[0126] The invention of claim 11 uses metal balls for the supports. Bythis construction, it is made possible to use the surface area of thecircuit board more effectively, and the piezoelectric oscillator can befurther miniaturized.

[0127] The invention of claim 12 is a piezoelectric oscillator in whicha circuit board with circuit components making up an oscillating circuitand a temperature-compensating circuit mounted on the bottom side andexternal terminals formed on the top side and a piezoelectric vibratorare joined together by bonding the bottom terminals of the piezoelectricvibrator and the external terminals on the top side of the circuitboard, and in addition metal balls attached to the bottom side of thecircuit board are used as terminals for external connection. By thisconstruction, the piezoelectric oscillator can be further miniaturized.

[0128] The invention of claim 13 is a piezoelectric oscillator in whichcircuit patterns and lands are formed on the bottom of the piezoelectricvibrator and circuit components making up an oscillating circuit and atemperature-compensating circuit and metal balls are mounted on thebottom of the piezoelectric vibrator, and the metal balls serve as theterminals for external connection. This construction can lower theprofile of the piezoelectric oscillator.

1. A piezoelectric oscillator, characterized by comprising apiezoelectric vibrator with a piezoelectric vibrating element housed ina package and bottom terminals formed on the outer side of the bottom ofthe package, a circuit board with at least one electronic circuitcomponent mounted and conductor patterns formed on the top side, andcolumnlike supports which mechanically and electrically connects thebottom terminals of the piezoelectric vibrator and the conductorpatterns on the circuit board.
 2. A piezoelectric oscillator comprisinga flat circuit board with circuit components making up an oscillatingcircuit mounted on the top side and external terminals formed on thebottom side and a piezoelectric vibrator fixed above the circuit boardwith a predetermined space by columnlike supports fixed to the top sideof the circuit board, characterized in that the piezoelectric vibratorhas a piezoelectric vibrating element housed in a hermetically sealedpackage and bottom terminals connected with the excitation electrodes ofthe piezoelectric vibrating element formed on the outer side of thebottom of the package; and the columnlike supports are separate partsfrom the piezoelectric vibrator and the circuit board, the bottom of thecolumnlike supports being mechanically and electrically fixed to landsformed on the top side of the circuit board, and the top of thecolumnlike supports being mechanically and electrically bonded to thebottom terminals of the piezoelectric vibrator.
 3. A piezoelectricoscillator comprising a flat circuit board with at least circuitcomponents making up an oscillating circuit mounted on the top side andexternal terminals formed on the bottom side and a piezoelectricvibrator, fixed together and electrically connected by means ofcolumnlike supports, characterized in that: the columnlike supports aresmall pieces of an insulating material with conductors formed on the topand the bottom and connected by a connecting conductor; the circuitboard has support-fixing lands for bonding the conductors on the bottomsof the columnlike supports thereto formed on the top side; and thepiezoelectric vibrator houses a piezoelectric vibrating element in ahermetically sealed package and has bottom terminals to be bonded to theconductors on the tops of the columnlike supports formed on the bottomof the package.
 4. The piezoelectric oscillator of any one of claims 1to 3, wherein said columnlike supports are ceramic blocks withconductors formed on the top and the bottom and connected by aconnecting conductor.
 5. The piezoelectric oscillator of any one ofclaims 1 to 3, wherein said columnlike supports are metal blocks ormetal balls.
 6. The piezoelectric oscillator of any one of claims 1 to3, wherein circuit-components with the highest mounted height are usedfor said columnlike supports.
 7. The piezoelectric oscillator of any oneof claims 1 to 6, wherein said columnlike supports are circular,elliptic, or oval in cross section.
 8. A method of manufacturing apiezoelectric oscillator comprising a flat circuit board with at leastcircuit components making up an oscillating circuit mounted on the topside and external terminals formed on the bottom side and apiezoelectric vibrator fixed together and electrically connected bycolumnlike supports with conductors formed on the top and bottom andconnected by a connecting conductor, characterized by comprising thefollowing steps: forming the circuit patterns, support-fixing lands andterminals for the piezoelectric oscillator in each partition on a largemother circuit board, and mounting the circuit components for thepiezoelectric oscillator on each partition on the mother circuit boardto form a block of the circuit boards of the piezoelectric oscillators;making a block of the columnlike supports which are disposed to fit onthe support-fixing lands of the corresponding circuit boards of theblock of the circuit boards, and fixing the columnlike supports of theblock of the columnlike supports to the support-fixing lands on thecorresponding circuit boards of the block of the circuit boards,electrically connecting the conductor on the bottom of each columnlikesupport and the support-fixing land by putting the block of thecolumnlike supports onto the block of the circuit boards; cutting theblock of the circuit boards together with the block of the columnlikesupports to separate the individual circuit boards; and mounting thecrystal vibrator on the columnlike supports of each circuit board bybonding the bottom terminals of the piezoelectric vibrator to theconductors on the tops of the columnlike supports.
 9. The method ofmanufacturing a piezoelectric oscillator of claim 8, wherein the blockof the columnlike supports comprises a latticework part with holescorresponding to the circuit boards of the block of the circuit boardsand the columnlike supports projecting from the latticework part intoeach hole so as to fit on the support-fixing lands of the correspondingcircuit board.
 10. A piezoelectric oscillator comprising a flat circuitboard with circuit components making up an oscillating circuit mountedon the top side and bottom terminals formed on the bottom side and apiezoelectric vibrator held above the circuit board with a predeterminedspace by a support frame, characterized in that; the piezoelectricvibrator has a piezoelectric vibrating element-housed in a hermeticallysealed package and bottom terminals on the outer side of the bottom ofthe package; the support frame has terminals for connecting the bottomterminals of the piezoelectric vibrator thereto on the top side andterminals for being connected to the circuit board formed on the bottomside; and the circuit board has a larger surface area than the outsidedimensions of the support frame, and has lands for connecting the bottomterminals of the support frame thereto and lands for mounting circuitcomponents thereon inside and outside the support frame on the top sideof the circuit board.
 11. The piezoelectric oscillator of claim 10,wherein a plurality of metals are used instead of the support frame. 12.A piezoelectric oscillator comprising a flat circuit board with circuitcomponents making up an oscillating circuit mounted on the bottom sideand external terminals formed on the top side and a piezoelectricvibrator with bottom terminals formed on the bottom of the package,fixing together by bonding the external terminals of the circuit boardand the bottom terminals of the piezoelectric vibrator; and metal ballsserving as supports and external terminals are fixed to the bottom sideof the circuit board.
 13. A piezoelectric oscillator, characterized byhaving a piezoelectric vibrating element housed in a hermetically sealedpackage, circuit patterns for an oscillating circuit and lands forfixing supports thereto formed on the bottom of the package, and circuitcomponents and metal balls serving as supports and external terminalsmounted on the bottom.